SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b4098b8f8c7d61642c457aacd19621e4ad03c619df9ff823412756e6f0e5fea' 
  AND token = 'Vl0Iw2zddu3G/yM8L/4hTz+EQBUCvVdfzIWnevxPBks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}